Take a look at the "exclude a folder from a backup" section. To only include a single (or a few) folders, you'd follow those general steps, but:
- Instead of including 'Backup - all files' in the 2nd tab, include 'Exclude all files'
- Add the folder(s) and files(s) you want to copy in the 3rd tab, and make sure the command in front is copy
That's all there is to it.